1. Field of the Invention
The present invention relates to a hydrodynamic torque converter, comprising a housing arrangement, which is or can be filled with fluid, and which is to be connected by a connecting area to a drive element for rotation in common around an axis of rotation; a pump wheel; and a turbine wheel, which is to be connected to a takeoff element in the housing arrangement. A supporting/sealing hub area is provided on the axial side of the housing arrangement facing away from the connecting area.
2. Description of the Related Art
A hydrodynamic torque converter of this type is known from DE 199 08 123 A1. The hydrodynamic torque converter, which is to be connected on the drive side to the crankshaft of an internal combustion engine and to be connected on the takeoff side via the turbine wheel to a gearbox input shaft, has, on the axial side facing the gearbox, an essentially sleeve-like or hollow shaft-like hub, which is intended to fulfill various functions. This hub is attached at one axial end by welding to the radially inner end of the housing arrangement, and at its other axial end, which, in the assembled state of a drive train, is located inside a gearbox housing; the hub has a rotational driver formation, which, during rotational operation, drives an oil pump located inside the gearbox housing, so that oil, as the working fluid, can be transported into the interior of the housing arrangement. Between the two axial ends of this hub, the outside circumference forms a sealing surface, on which a sealing arrangement acts to establish a fluid-tight connection with respect to the gearbox housing. The end surface at the axial end of this hub which is connected to the radially inner area of the housing arrangement forms a bearing surface or support surface for a bearing, which axially supports a stator located inside the housing arrangement. This hub, furthermore, is mounted or supported on its inside surface with respect to a support shaft by another support arrangement. The support shaft carries the previously mentioned stator but is fixed in position on the gearbox housing and thus does not rotate along with the other components during rotational operation.
Various problems arise as a result of this integration of a large number of different functions in a single component. For example, slight displacements of the gearbox housing with respect to the hydrodynamic torque converter can lead to damage to the sealing arrangement which rests on the sealing surface of the hub, because this hub projects into the gearbox housing more-or-less freely, that is, without additional support. In addition, because of the various functions which it must fulfill, the hub must be manufactured with a high degree of precision and must also be subjected to expensive grinding and deburring operations especially so that the sealing arrangement, usually designed as a sealing ring which rests on the sealing surface, can be installed properly. This also applies to the axial end surface which provides the bearing surface for the axial bearing which supports the stator.